Process for reducing the pour point of crude oil and the like



Sept 3, 1968 s. E. TUNG ETAL 3,400,072

PROCESS FOR REDUCING THE POUR POINT OF CRUDE OIL AND THE LIKE l FiledMarch 24, 1965 3 Sheets-Sheet l Umb/7 /w BY o-wAfao MQ/N/A/CH L" @ffmAfro/ener Sept. 3, 1968 s. E. TUNG ETAL Filed March 24. 1965 BL END 5 5LEND zo ao 40 P000 po/A/r pp/OQ ro m54 wwf-N7' -,000,49 ,O0/N7' ,4F-TFPman TM5/vr PROCESS FOR REDUCING THE POUR POINT OF CRUDE OIL AND THE LIKE3 Sheets-Sheet 2 I NVENTOKS [n SHA@ TUA/q @WARD ME//v/NCH United StatesPatent O 3,400,072 PROCESS FOR REDUCING THE POUR POINT OF `CRUDE OIL ANDTHE LIKE Y Shao E. Tung and Edward Mclninch, Ponca City, Okla.,assignors to Continental Oil Company, Ponca City, Okla., a corporationof Delaware Filed Mar. 24, 1965, Ser. No. 442,259

15 Claims. (Cl. 208-120) This invention relates to a process forreducing the pour point of hydrocarbon mixtures derived from petroleumand including crude petroleum, and straightrun and cracked fractions ofpetroleum. More particularly, the present invention relates to a methodfor catalytically converting a relatively high pour point mixture ofpetroleum-derived hydrocarbons to a mixture ot hydrocarbons having alower pour point than the mixture prior to subjection to such catalyticconversion.

An important property of crude petroleum and certain distillates derivedtherefrom is the pour point. The pour point is the temperature at whichthe mixture of hydrocarbons will begin to iiow under gravitationalinfluence and with certain standard conditions applied. Its value, whenconsidered conjunctively with other properties, can provide anindication of the end products which can be derived from hydrocarbonmixtures. The pour point is also indicative of the ease with which thecrude petroleum or distillate fraction can be pumped through |pipelines-under various environmental conditions.

As an example of the important significance of the pour pointcharacteristic of crude petroleums, the oils produced in the majority ofthe Libyan Ifields have pour points which range from 25 F. to 45 F. TheMiddle East crudes, on the other hand, have a substantially lower pourpoint, averaging about F. In keeping with the correlation between pourpoint and end products to which reference has 4been made, a largerportion of the Middle East crude oil can be economically converted todistillate suitable for Diesel fuel, etc., than the portion of Libyancrude which can be converted to such oils at the same or a comparablecost- Stated diierently, a greater portion of the Middle East crudes,can be eco'- nomically converted to distillate than in the case of theLibyan crudes.

Since thevdernand of the European market is primarily for disillate, theLibyan crude oilsA |presently suffer an economic disadvantage relativeto the Middle East petroleum. It is therefore desirable to investigatemethods of more economically converting a larger portion of the Libyanand other crudes to distillate stocks. One such method which we havediscovered entails treating the high pour point crude oil or a fractionthereof to reduce the pour point. A significantly larger portion of theproduct resuling from our process can be economically converted todistillate and such pour point reduction further serves to make thetreated crude oil or hydrocarbon mixture more susceptible to pipelinetransport in cold climates.

The process of the present invention is a catalytic conversion procedureby which the overall molecular makeup of a complex mixture ofhydrocarbons, such as crude oil, is changed so as to yield a mixture of-hydroselected carbons having a reduced |pour point. Broadly described,the present invention comprises contacting, at a tempera# ture in therange of from about 350 F. to about 850 F., a petroleum-derived mixtureof hydrocarbons selected from the group consisting of crude pertoleumand fractions thereof with a catalyst comprising a crystallinealuminosilicate material in which the crystalline structure is athree-dimensional framework containing cation sites and Si04 and A104tetrahedra bonded through oxygen in regular orientation and forming anintracrystalline pore system having an average pore size of from about 6A to about 14 A., the silicon to aluminum ratio in said aluminosilicatematerial being from about 1:1 to about 4:1, said crystalline structurebeing further characterized by the absence of monovalent cations fromsome of the available cation sites in said theree-dimensional structure.

The pressure which is applied to the system as the hydrocarbon mixtureis contacted with the catalyst can vary from atmospheric pressure up toabout 2,000 p.s.i.g.

The hydrocarbon mixtures may be contacted with the catalyst in severalways, such as by using a iiuidized bed of the catalyst, or using a fixedbed. The fixed bed pro-l cedure is presently preferred, however, andwhen this technique is employed, the space velocity utilized in passingthe hydrocarbon mixture through the catalyst bed can range from about0.5 pound of the hydrocarbon mixture per pound of catalyst per hour toabout 7 pounds of the hydrocarbon mixture per pound of catalyst perhour.

The type of catalyst materials which are preferably employed aretdervived from aluminosilicate materials of the type known as zeolites.The zeolites may be of natural or synthetic origin, provided that thepore size and silicon to aluminum ratio are as hereinbefore defined, andprovided that some of the available cation sites in the zeolitecrystalline structure have either been divested of cations(decationized), or that a portion of the cation sites is occupied bypolyvalent cations, as opposed to monovalent cations.

By passing the hydrocarbon mixture through a catalyst bed of thecharacter described and at a rate within the range indicated, asubstantial reduction in the pour point of the mixture can be effected.Thus, lwith typical Libyan crude oils, we have been successful inreducing the pour point of the crude oil by as much as 55 F. in a singlepass of the crude oil through a fixed catalyst bed.

From the foregoing description of the invention, it will have becomeapparent that it is a major object of the invention to provide a processfor reducing the pour point of petroleum-derived mixtures ofhydrocarbons.

Another object of the invention is to provide a simple procedure foreconomically converting a greater portion of crude petroleums tohydrocarbon mixtures having properties and economic value similar todistillate fractions of petroleum.

An additional object of the present invention is to renderpetroleum-derived mixtures more suitable for pipeline transport,especially in winter or in colder climates.

Another object of the invention is to provide a catalytic conversionprocess which can be very easily practiced by operating personnel ofrelatively little technical training, and which can be used to reducethe pour point of crude oil and fractions derived therefrom.

Additional objects and advantages of the invention will become apparentas the following detailed description of the invention is considered inconjunction with the accompanying drawings which graphically depicttypical results obtained in the practice of the invention.

In the drawings:

FIGURES 1 and 4 are two graphs illustrating some of the processconditions employed, and results obtained, when a crude oil distillatefraction was subjected to the process of the present invention andemploying one of the types of catalyst suitable for use in theinvention.

FIGURES 2 and 5 are two graphs similar to those depicted in FIGURES 1and 4, but based upon the results obtained when a Libyan crude oil wassubjected to the process of the invention and using a different catalystfrom that employed in the procedure which yielded the resultsgraphically portrayed in FIGURES 1 and 4.

FIGURES 3 and 6 are two graphs similar to those shown in FIGURES l, 2,4, and 5, but depicting results obtained when a Libyan crude oil wassubjected to catalytic conversion using yet a different type of catalystin the process of the invention.

Before considering certain specific examples of the practice of theinvention, and the accompanying drawings, which graphically depict theresults obtained from such practice, the materials used in the processand the conditions employed therein will be specifically considered.

The types of hydrocarbon mixtures to which the invention is applicablewill first be described. In general, any crude oil or a straight-run orcracked fraction of the crude oil can be subjected to the catalyticconversion process. Since a major object of the invention is to areduction in pour point of the hydrocarbon mixture, the starting mixtureof hydrocarbons preferably has a pour point of at least 15 F. asdetermined by ASTM D-97. As a general proposition, the higher the pourpoint of the starting material, the greater the reduction in pour pointwhich can be achieved by the use of the invention.

Whether raw crude oil will be directly subjected to the process, or willinstead first be topped, and the distillate and residual cuts thensubjected to the catalytic conversion process of the invention toachieve pour point reduction, will depend upon the plant facilitiesavailable, and the process economics dictated by the market and otherfactors. For example, where a low pour point distillate is in greaterdemand than fuel oil as hereinbefore described, and it is desired toincrease the yield of the former material without an uneconomic increasein the cost of such production, the crude oil which is available and ofundesirably high pour point may be treated in any one of three ways.First, the entire uncut crude oil may be contacted with the catalystused in the invention to reduce the pour point of the crude, and thusimpart to it a character permitting a higher distillate fraction to beyielded upon ultimate refining. Alternatively, the crude oil may betopped and the entire topped fraction may then be subjected to contactwith the catalyst to adjust the pour point.

As a final alternative, the distillate fraction from the crude may befurther fractionated to remove the higher boiling portion thereof andthis higher boiling fraction can be subjected to catalytic conversion.The converted higher boiling fraction is then blended back with thelower boiling portion of the topped crude oil. This blend is then adistillate having the desired properties, including a relatively lowpour point.

A typical crude oil of Libyan origin to which the present invention maybe effectively applied t increase the yield of distillate has thefollowing properties:

Gravity, A.P.I. 38.6 Pour point F 40 A crude distillate fraction derivedfrom the Libyan crude oil which has been used in the practice of thepresent invention has the following properties:

Gravity, A.P.I 36.8

Pour point F 20 Kinematic viscosity 100 F centistokes 3.873

ASTM D86 distillation, vol. percent received 760 mm. Hg:

I.B.P 464 The properties of the crude oil and distillate fraction as setforth above are based upon accepted tests of the American Standards forTesting Materials as followsgravity, ASTM D-287; pour point, ASTM D-97;kinematic viscosity, ASTM D-445; and distillation, ASTM D-86.

In other terms, the typical Libyan crude oils which I have found can beparticularly beneficially subjected to the process of the invention are,by the U.S. Bureau of Mines method of classification, intermediatetypes, grading toward parainic in the gas oil and residual fractions.

The catalyst used in the process of the invention comprises analuminosilicate material of crystalline structure. This crystallinestructure is a three-dimensional framework containing a plurality ofcation sites and containing SiO4 and A104 tetrahedra bonded to eachother through oxygen in regular orientation so as to form a uniformintracrystalline pore system. The pores of the crystal lattice have anaverage diameter of at least about 6 A. when the cation sites areactually occupied by cations to permit the passage of the hydrocarbonmolecules therethrough. Preferably, the pore size is at least about 8A., and best results to date have been obtained using a crystallinestructure having a pore size of about 10 A. Crystalline structures inwhich the diameter of the pores is as high as about 14 A. can be usedeffectively.

The crystalline aluminosilicate employed is further characterized by aSi to Al ratio of from about 1:1 to about 4:1. Preferably, this ratioexceeds l to 1, and at the present time, a silicon to aluminum ratio ofabout 2.5:1 is considered the preferred proportion of these two majorelemental types in the crystalline structure.

At this point it should be pointed out that though the catalystpreferably consists essentially of the described crystalline form ofaluminosilicate, large amounts of amorphous aluminosilicate can also beincluded in the catalyst, though the predominantly amorphous materialcontaining only very small amounts of the crystalline catalyst does notat this time appear to give as great a reduction in pour point. Whereamorphous aluminosilicate is present in the catalyst, it preferablycontains silicon and aluminum in the ratio of from about 3:1 to about4:1.

The crystalline structure present in the catalyst may be further anddifferently described as containing silicon and aluminum atoms inIfourfold coordination and bonded to each other through oxygen atoms soas to form the SiO4 and A104 tetrahedra herein-before mentioned. In thisarrangement, the negative charge on each of the A104 tetrahedrons isnormally balanced, both in the naturally occurring crystallinealuminosilicates and in synthetic materials of this type, by theinclusion of an electropositive cation. Thus, a number of cation sitesexist throughout the crystalline structure.

An important characteristic of the aluminosilicate crystals suita-blefor -use in the catalyst in the process of the present invention is thatthe cation sites in the crystal be either vacant (that is, not occupiedby any cation whatsoever), or be occupied by a polyvalent cation.Statedy differently, the crystalline structure used in the catalyst ofthe invention is characterized by the absence of monovalent cations fromla portion of the available cation sites in the three-dimensionalcrystalline structure.

The extent to which monovalent cations are absent from the availablecation sites in the crystalline structure is of some importance. Ingeneral, the greater the number of the cation sites which have beeneither decationized and are therefore vacant, or, alternatively, havebeen filled with polyvalent cations by a process of ion exchange, thegreater the activity of the catalyst in pour point reduction. It hasbeen observed that the activity of the catalyst increases substantiallywhen it has been decationized to the extent of about percent (that is,all ions have been removed from at least about 10 percent of theavailable cation sites in the crystalline structure). It has also beenfound that a substantial increase in catalytic activity occurs when atleast about 30 percent of the monovalent alkali metal cations whichgenerally occupy the cation sites in naturally occurringaluminosilicates, and in most of the synthetic aluminosilcates now made,have been replaced by polyvalent cations. Further, the catalyticactivity of the crystals increases as an increasing proportion of thecation sites are either decationized or occupied by polyvalent cations.Preferably, the aluminosilicate crystalline structure has either been atleast about 40 percent decationized, or has at least about 70 percent ofthe cation sites occupied by polyvalent cations. At the 70 percent levelof polyvalent cation occupancy, the remaining monovalent ion content,expressed as sodium, may amount to about 3 Weight percent of thecatalyst.

Where the cation sites are occupied to a substantial degree bypolyvalent cations to activate the catalyst, divalent cations are thepolyvalent cations which are preferably employed, and of this ionictype, it is preferred to employ magnesium, calcium and barium as thepolyvalent cation in the crystalline structure.

Some additional advantage may be gained by including in a minor portionof the total available cation sites, cations derived from the metals ofGroup VIII of Mendeleevs periodic table. Of this group of metals, it ispreferred to include the ions of platinum, iridium, ozmium, palladium,rhodium and nickel in the crystalline structure in an amount rangingIfrom about 0.1 weight percent to about 10 Weight percent of thecrystalline structure. The most preferred Group VIII ionic species arederived from platinum and palladium.

CTI

The described aluminosilicate structures embrace, but are not limitedto, the natural and synthetic zeolites, and these materials have beenfound to be especially well suited for use in the invention. They havebeen either partially decationized to remove the monovalent cationswhich are usually included in the crystalline lattice, or are subjectedto ion exchange to replace a portion of the monovalent cations with thepolyvalent cationic types hereinbefore described. In general, thezeolite crystalline structure will include the Si04 land A104 tetrahedrahereinbefore described, and will further include in association withsuch tetrahedra, alkali metal cations Iwhich satisfy or Ibalance thenegative charge on each of the A104 tetrahedrons. To prepare thecatalyst used in the present invention, these alkali metal cations maybe removed by decationization procedures well understood in the art, ormay be replaced by polyvalent cations using ion exchange techniquesequally well understood. It is reiterated that all of the alkali metalcations need not be removed from the crystalline lattice or replaced bypolyvalent cations. Catalytic activity commences to be perceptible assoon as a small number of the alkali metal ions are removed or replaced,and increases as an increasing number of the cation sites in the crystalare either vacated or lled with polyvalent cations.

As previously indicated herein, the mixture of hydrocarbons can becontacted with the aluminosilicate catalyst material either by afiuidized catalytic process, or by passing the hydrocarbon mixturethrough a fixed bed of the catalyst. Where the fixed bed procedure isernployed, the size of the catalyst pellets can vary widely. Forexample, a particle size diameter of from about 1/16 inch up to about 1Ainch can be very conveniently employed, and the preferred particle sizerange is from about Ms inch to about 9/16 inch in diameter. Where aportion of the cation sites in the aluminosilic-ate crystallinestructure are occupied by ions derived from one of the Group VIIImetals, as hereinbefore described, the catalyst is preferablypre-treated to reduce them to their lowest valence state by passinghydrogen gas through the catalyst and in contact therewith for asubstantial period of time prior to commencement of the process of theinvention. For example, the catalyst may be conditioned for use bypassing hydrogen -gas through the bed at a temperature of 1,000n F. forabout 4 hours prior to commencing the process.

The conditions applied to the system as the hydrocarbon mixture iscontacted with the catalyst are of some importance. The temperature ofthe catalyst at the time of contact is from about 350 F. to about 850 F.Preferably, the temperature employed during the catalytic conversion isfrom about 550 F. to about 700 F. The pressure employed can range fromatmospheric pressure to about 2,000 p.s.i.g. Where the system ismaintained under pressure during the catalysis, such pressure ispreferably maintained by utilizing hydrogen gas under pressure incontact with the catalyst. The space velocity utilized in passing thehydrocarbon mixture through the catalyst bed can range from about 0.5pound of the hydrocarbon mixture per pound of the catalyst per hour toabout 7 pounds of the hydrocarbon mixture per pound of the catalyst perhour. Preferably, from about 2 to about 5 pounds of the hydrocarbonmixture per pound of catalyst per hour is the space velocity employed.

In order to maintain the activity and extend the life of the catalyst,it is preferable to include with the liquid hydrocarbon mixture passedin contact with the catalyst, entrained hydrogen gas, with the moleratio of the hydrogen gas to the hydrocarbon liquid feed stock beingfrom about 1:1 to about 10:1. A hydrogen to feed stock mole ratio offrom about 3:1 to about 7:1 is preferably employed.

In order to `further describe and more clearly illustrate the practiceof the present invention, a number of examples of such practice arehereinafter set forth.

7 EXAMPLE r A Libyan crude oil of the following properties was subjectedto the catalytic conversion process of the present invention:

portion of the liquid product yielded in the first run was carried out.A third pass in which `60 ml. of the liquid product from the second passwas contacted with the catalyst was also completed.

Property Test Method Value Gravity, A.P.I ASTM D-287 38.6 Gravity,specific, 13o/60 F-- ASTM D-1250 o. 8319 Density at 15 C., KgJLiter ASTMD-1250 0.8315

Kine- Saybolt Engler matic Univ. Degrees Viscosity:

At 70 F. (21.1 C.) ASTM D-445 7.50 50.33 1. 61 At 100 F. (37.8 C.) ASTMD-445. 4.64 41. 20 1. 37 At 122 F. (50.0 C.) ASTM D-445 3. 52 37. 741.27 At 130 F. (54.4 C.) ASTM D-445 3. 21 36. 77

Characterization Factor- 11. 90

Mean Molecular Weight 212 Water and Sediment, Vol. Percent- O. 24 Waterby Distillation, Wt. Percent.-- 0.0 Acidity, Total, Mg. KOH/Gm 0.17Carbon Residue, Ramsbottom, Wt. ASTM D524 1.83

Percent. Asphaltenes, Wt. Percent IP-43 0.71 Sulfur, Total, Wt.Percent-- ASTM D-1522... 0. 32 Ash, Wt. Percent ASTM D-482 0.007Metallic Elements, ppm.:

n- 1. 8 Nickel.- 4. 9 Vanadian 1. 4 Pour Point ASTM D 40 Chlordes as NU.O.P. 22 18.2 Reid Vapor Pressure. ASTM D-323 7. 0 Disltillaton, Vol.Percent Ree. at 760 mm.

ASTM D-86 115 ASTM D-8G 181 ASTM D-86 227 ASTM D-86 270 310 350 393 433473 514 554 592 630 666 ASTM D-8G 708 A tubular glass reactor of 10 mm.inside diameter and 70 mm. length was packed to a height of 38 mm. withsix grams of aluminosilicate catalyst having a particle size of from 8to 14 mesh. The particulate catalyst employed was a treated syntheticzeolite of the type marketed by t-he Union Carbide Co. under thetrademark Linde Molecular Sieve, type Y, number SKI l0. The zeolitecontained 5.2 weight percent manganese which had been incorporatedtherein by cation exchange resulting in replacement of alkali metalcations yfrom a substantial number of the total available cation sitesin the crystalline structure. The catalyst was further loaded with 0.5weight percent palladium ions. The crystalline material had a pore sizeof 10 A. and a silicon to aluminum ratio of 2.5.

Prior to passing the crude oil through the xed bed of catalyst in thereactor, the palladium-carrying catalyst was pre-conditioned by passinghydrogen gas through the bed at a flow rate of 2O ml. per minute for 4hours while maintaining the hydrogen gas at a temperature of 1,000 F.

The Libyan crude oil was next passed through the catalyst bed in thereactor at a rate of 0.5 ml. per minute (equivalent to a space velocityof pounds of crude per pound of catalyst per hour). The system wasmaintained at atmospheric pressure during the run and the temperatureemployed was 630 F. The liquid product from the catalytic conversion wascollected, as was the gas generated by the catalysis. The pour point ofthe liquid product was measured and compared with the pour point of theoriginal crude prior to treatment. The amount of gas generated as thecrude oil was passed through the catalyst bed was also measured andrecorded. After completing the rst pass of 170 ml. of the crude oilthrough the catalyst bed, a second pass of a substantial The results ofthe catalytic conversion runs using crude oil of the type described areset forth in Table I.

TABLE L POUR POINT REDUCTION Original Crude-- 35 Processed Crude (FirstPass) Processed Crude (Second Pass) 10 Processed Crude (Third Pass) 10Gas Generation M1. of crude throughput Avcrage Gas ml./

Total Gas ml. crude Evolved, mi.

First Pass:

0-10- 1, 350 135 10-30 210 10. 5 -50 58 2. 9 -70 62 3.0 -90. 38 1. 9S10-110. 37 1. 9 -130 35 1. 7 130450 32 1.6 -170 32 1. 6 Second Pass:

The data in Table l indicate that one pass through the catalyst bed issuficient to achieve substantially all of the pour point reduction whichcan be effected by contact with the catalyst. Thus, a pour pointreduction of 25 F. was obtained in the rst pass, and the pour point wasnot significantly further lowered by the second and third passes of thematerial through the catalyst bed. While the above conditions have beendisclosed as having utility with a lixed catalyst bed, it should bepointed out that they are equally applicable to a uidized bed 9loperation, except that the space velocity parameter will require slightmodification.

EXAMPLE II Property Test Method Value Gravity, A.P.I-, ASTM D-287. 36. 8Flash Point, RM., F. ASTM-D-93 235 Pour Point, F ASTM D-97. 20 Viscosityat 100 F Cs ASTM D-445. 3. 873 Refractive Index, ND20 C ASTM D-1218. 1.4676 Sulfur, Total Wt percent.-- ASTM D-1552 0.21 Distillation, F., I.B.ASTM D-86. 464 Vol ASTRID-86. 482 10% Vol ASTM D-86. 491 %Vol. ASTM D-86504 Vol ASTM D-86. 516 Vol.- ASTM D-86. 530 Vol ASTM D-86 545 Vol.. ASTMD-S- 562 Vol.- ASTM D-86- 581 Vol. ASTM D-86- 601 Vol.. ASTM D-86 614Vol.. ASTM D-86. 639 E.P ASTM D86 651 The distillate was subjected tocatalytic conversion by contact with a fixed catalytic bed of the typedescribed in Example I. The catalyst employed was identical to that usedin Example I, and the pre-treatrnent of the catalyst bed by passinghydrogen gas therethrough, as well as the temperature, pressure andspace velocity conditions used during the process, were the same as inExample I.

The results obtained from the catalytic conversion are portrayed by thegraphs shown in FIGURES l and 4. In FIGURE 4, the ml. of gas generatedby the catalyst per ml. of distillate feed to the catalyst bed isrepresented by the lowermost curve in this graph and the values areplotted on the ordinate axis to the left of the graph.

The rate of feed of the distillate in ml./minute is plotted as thecentral curve on FIGURE 4 and the values for this parameter are locatedon the ordinate axis to the right of the graph. The liquid product whichwas collected per ml. of distillate feed (in ml. per ml.) is plotted asthe uppermost curve and the values for this curve also appear on theordinate axis to the right. The abscissa of both FIGURES l and 4 showsthe total distillate feed passed through the catalyst bed inmilliliters.

In FIGURE l, the pour .points of the distillate feed and the liquidproduct are represented by the upper and lower curves, respectively. Thepour point of the liquid product was measured for several differentvalues of tota distillate feed.

In referring to FIGURES 1 and 4, it will be noted that the pour point ofthe distillate was depressed 10 F. by passage through the catalyst bed.It will further be noted that, except for the initial liquid throughput,substantially all of the liquid distillate was recovered, aftercatalytic conversion, as a liquid product and relatively little of thetotal product was in gaseous form. The total percentage of the liquidfeed recovered as liquid product, after the first 20 ml. of throughput,averaged 99.9 weight percent. Thus, no significant loss by change ofstate or holdup in the catalyst bed occurs in the process of theinvention.

EXAMPLE III A Libyan crude oil having a pour point of 50 F. was passedthrough a six gram bed of catalyst extending to a height of 38 mm. in aglass reactor tube of the size described in Example I. The catalyst wasa synthetic zeolite similar to that used in the process described inExample I except that the zeolite had been decationized to the extent ofremoving all cations from about 70 percent of the available cationsites, the remaining sites remaining occupied by sodium ions. No loadingof the catalyst with one of the Group VIII metal ions was employed. Thecatalyst was not subjected to contact with hydrogen gas prior to orduring the process. The temperature, pressure and space velocityconditions used during the run were those used in the Example Iprocedure.

The results of pour point, liquid product and gas .product measurementsare portrayed in the graphs shown in FIGURES 2 and 5 which are laid outsimilarly to the FIGURE 1 and FIGURE 4 graphs hereinbefore described. Itshould be pointed out, however, that the pour point measurements on theliquid product as graphed in FIG- URE 2 were made on composite blendswhich were made by combining several of the liquid product cutscollected at the intervals indicated on the uppermost curve in FIG- URE5. It is of interest to note that the greatest pour point reduction, anamount of 85 F. (from 50 F. to -35 F.), occurred in the case of thefirst blend collected.

The blend was a composite of cuts taken during the initial v EXAMPLE 1VThe graphs of FIGURES 3 and 6 depict, in similar fashion to the FIGURE 2and FIGURE 5 graphs, the results obtained when the process described inExample III was carried out, `using the same crude oil and an identical`decationized catalyst system except that the catalyst contained 0.6weight percent palladium ions. It will be noted that the initialreduction in pour point is less pronounced in the case of palladiumloaded catalyst, but that the average overall pour point reduction ofabout 50 F. is greater than in the case of the decationized catalystwithout the inclusion of the palladium ions.

From the foregoing discussion of the invention and the examples of itspractice which have been described, it will be perceived that theprocess provides a technique for quickly, easily and economicallyreducing the pour point of mixtures of hydrocarbons without theconcurrent loss of a significant amount of the treated mixture. Gasgeneration resulting from the catalysis does not occur to a degreesufficient to constitute any problem of separation, disposal or safetyhazard. The conditions of temperature and pressure used in the processare not suiciently stringent or critical to prevent the successfulemployment of the process by personnel having relatively littletechnical training.

In achieving the reduction in the pour point of the hydrocarbonmixtures, the end products which may ultimately be derived uponrefinement of the hydrocarbon mixtures can be beneficially altered, andthe ease with which the mixtures can be pumped and moved throughpipelines at relatively 'low temperatures is improved.

The foregoing description of the invention is intended to be exemplaryof its practice and does not provide a comprehensive statement of allmodifications and variations which may be employed in selecting thematerials to be used or the conditions to be imposed. Thus, in additionto the natural and synthetic zeolites mentioned as specific examples ofthe crystalline structure which is to be used as a catalytic material inthe process of the invention, other aluminosilicate crystallinematerials having the defined structure, such as Faujasite and Modenite,can also be used. The hydrocarbon mixtures to which the process isapplied are also subject to considerable variation, and includedistillates and gas oils of widely varying properties, as well asvarious crude oil types. Other variations in process conditions andmaterials used will readily occur to those skilled in the art and areconsidered to be encompassed by the spirit and scope of the presentinvention if the basic principles of the invention are still employed ina catalytic conversion process to obtain pour point depression.

I claim:

1. A process for reducing the pour point of crude petroleum and thelike, said pour point reduction being effected without the production ofsubstantial gas due to cracking, and to recover at least 90 weightpercent of the charge material as liquid product, said processcornprising contacting in the absence of added hydrogen gas said mixtureat a temperature in the range of from about 350 F. to about 850 F. witha catalyst comprising an aluminosilicate material of predominantlycrystalline structure in which the crystalline structure is athree-dimensional framework containing cation sites and SiO4 and A104tetrahedra bonded to each other through oxygen in regular orientationand forming a uniform intracrystalline pore system having a pore size offrom about 6 A. to about 14 A., the silicon to aluminum ratio in saidaluminosilicate material being from about 1:1 to about 4:1, and saidcrystalline structure being further characterized by the absence ofmonovalent cations from some of the available cation sites in saidthree-dimensional structure and by the absence of Groups VI and VIIImetal cations or free metal from all of said available cation sites.

2. The process defined in claim 1 wherein said aluminosilicate materialis a zeolite containing polyvalent cations in sorne of said cationsites.

3. The process defined in claim 1 wherein said aluminosilicate materialfurther comprises, in addition to said crystalline structure, anamorphous aluminosilicate having a silicon to aluminum ratio of fromabout 3:1 to about 4: 1.

4. The process defined in claim 1 wherein said crystalline structure ischaracterized by a silicon to aluminum ratio exceeding 1.

5. The process defined in claim 1 wherein monovalent cations are absentfrom at least about percent of the available cation sites in thethree-dimensional framework of said crystalline structure.

6. The process defined in claim 1 wherein the pore size of saidcrystalline structure is from about 8 A. to about 11 A.

7. The process defined in claim 2 wherein said polyvalent cations aredivalent.

8. The process defined in claim 4 wherein said silicon to aluminum ratiois about 2.5 :1.

9. The process defined in claim 8 wherein the pore size of saidcrystalline structure is about 9 A. to about l0 A.

10. The process defined in claim 1 wherein at least about 30 percent ofthe available cation sites in said three-dimensional framework structureare occupied by polyvalent cations.

11. The process defined in claim 1 wherein said hydrocarbon mixture iscontacted with said catalyst under atmospheric pressure.

12. The process defined in claim 1 wherein at least 10 percent of theavailable cation sites are occupied by monovalent alkali metal cations.

13. The process defined in claim 7 wherein said valent cations areselected from the group consisting of calcium, magnesium and barium.

14. The process defined in claim 1 wherein said petroleum, derivedhydrocarbon mixture is an untreated crude petroleum, and contact of saidcrude petroleum with said catalyst is carried out under conditions oftemperature and pressure to effect a pour point reduction of at least 10F. and a conversion of the charge stock crude petroleum to gaseousproducts of less than 1 percent, based on the weight of the crudepetroleum, whereby substantially all of the crude petroleum is convertedto a lower pour point liquid material.

15. The process defined in claim 1 wherein said catalyst consists of acrystalline aluminosilicate material of the described crystallinestructure, and containing more than 3 weight percent monovalent alkalimetal cations disposed in said cation sites.

References Cited UNITED STATES PATENTS 3,243,366 3/1966 Kimberlin et al.208-28 3,132,087 5/1964 Kelley et al 208-60 3,140,249 7/ 1964 Plank etal 208--120 3,142,635 7/1964 Coonradt et al. 208-111 3,236,762 2/1966Rabo et al. 208--111 DELBERT E. GANTZ, Primary Examiner.

ABRAHAM RIMENS, Assistant Examiner.

1. A PROCESS FOR REDUCING THE POUR POINT OF CRUDE PETROLEUM AND THELIKE, SAID POUR POINT REDUCTION BEING EFFECTED WITHOUT THE PRODUCTION OFSUBSTANTIAL GAS DUE TO CRACKING, AND TO RECOVER AT LEAST 90 WEIGHTPERCENT OF THE CHARGE MATERIAL AS LIQUID PRODUCT, SAID PROCESSCOMPRISING CONTACTING IN THE ABSENCE OF ADDED HYDROGEN GAS SAID MIXTUREAT A TEMPERATURE IN THE RANGE OF FROM ABOUT 350*F. TO ABOUT 850*F. WITHA CATALYST COMPRISING AN ALUMINOSILICATE MATERIAL OF PREDOMINANTLYCRYSTALLINE STRUCTURE IN WHICH THE CRYSTALLINE STRUCTURE IS ATHREE-DIMENSIONAL FRAMEWORK CONTAINING CATION SITES AND SIO4 AND ALO4TETRAHEDRA BONDED TO EACH OTHER THROUGH OXYGEN IN REGULAR ORIENTATIONAND FORMING A UNIFORM INTRACRYSTALLINE PORE SYSTEM HAVING A PORE SIZE OFFROM ABOUT 6 A. TO ABOUT 14 A., THE SILICON TO ALUMINUM RATIO IN SAIDALUMINOSILICATE MATERIAL BEING FROM ABOUT 1:1 TO ABOUT 4:1, AND SAIDCRYSTALLINE STRUCTURE BEING FURTHER CHARACTERIZED BY THE ABSENCE OFMONOVALENT CATIONS FROM SOME OF THE AVAILABLE CATION SITES IN SAIDTHREE-DIMENSIONAL SRUCTURE AND BY THE ABSENCE OF GROUPS VI AND VIIIMETAL CATIONS OR FREE METAL FROM ALL OF SAID AVAILABLE CATION SITES.